github.com/kubiko/snapd@v0.0.0-20201013125620-d4f3094d9ddf/cmd/snap/cmd_alias.go (about)

     1  // -*- Mode: Go; indent-tabs-mode: t -*-
     2  
     3  /*
     4   * Copyright (C) 2016 Canonical Ltd
     5   *
     6   * This program is free software: you can redistribute it and/or modify
     7   * it under the terms of the GNU General Public License version 3 as
     8   * published by the Free Software Foundation.
     9   *
    10   * This program is distributed in the hope that it will be useful,
    11   * but WITHOUT ANY WARRANTY; without even the implied warranty of
    12   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    13   * GNU General Public License for more details.
    14   *
    15   * You should have received a copy of the GNU General Public License
    16   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    17   *
    18   */
    19  
    20  package main
    21  
    22  import (
    23  	"fmt"
    24  	"io"
    25  	"text/tabwriter"
    26  
    27  	"github.com/jessevdk/go-flags"
    28  
    29  	"github.com/snapcore/snapd/client"
    30  	"github.com/snapcore/snapd/i18n"
    31  	"github.com/snapcore/snapd/snap"
    32  )
    33  
    34  type cmdAlias struct {
    35  	waitMixin
    36  	Positionals struct {
    37  		SnapApp appName `required:"yes"`
    38  		Alias   string  `required:"yes"`
    39  	} `positional-args:"true"`
    40  }
    41  
    42  // TODO: implement a completer for snapApp
    43  
    44  var shortAliasHelp = i18n.G("Set up a manual alias")
    45  var longAliasHelp = i18n.G(`
    46  The alias command aliases the given snap application to the given alias.
    47  
    48  Once this manual alias is setup the respective application command can be
    49  invoked just using the alias.
    50  `)
    51  
    52  func init() {
    53  	addCommand("alias", shortAliasHelp, longAliasHelp, func() flags.Commander {
    54  		return &cmdAlias{}
    55  	}, waitDescs, []argDesc{
    56  		{name: "<snap.app>"},
    57  		// TRANSLATORS: This needs to begin with < and end with >
    58  		{name: i18n.G("<alias>")},
    59  	})
    60  }
    61  
    62  func (x *cmdAlias) Execute(args []string) error {
    63  	if len(args) > 0 {
    64  		return ErrExtraArgs
    65  	}
    66  
    67  	snapName, appName := snap.SplitSnapApp(string(x.Positionals.SnapApp))
    68  	alias := x.Positionals.Alias
    69  
    70  	id, err := x.client.Alias(snapName, appName, alias)
    71  	if err != nil {
    72  		return err
    73  	}
    74  	chg, err := x.wait(id)
    75  	if err != nil {
    76  		if err == noWait {
    77  			return nil
    78  		}
    79  		return err
    80  	}
    81  
    82  	return showAliasChanges(chg)
    83  }
    84  
    85  type changedAlias struct {
    86  	Snap  string `json:"snap"`
    87  	App   string `json:"app"`
    88  	Alias string `json:"alias"`
    89  }
    90  
    91  func showAliasChanges(chg *client.Change) error {
    92  	var added, removed []*changedAlias
    93  	if err := chg.Get("aliases-added", &added); err != nil && err != client.ErrNoData {
    94  		return err
    95  	}
    96  	if err := chg.Get("aliases-removed", &removed); err != nil && err != client.ErrNoData {
    97  		return err
    98  	}
    99  	w := tabwriter.NewWriter(Stdout, 2, 2, 1, ' ', 0)
   100  	if len(added) != 0 {
   101  		// TRANSLATORS: this is used to introduce a list of aliases that were added
   102  		printChangedAliases(w, i18n.G("Added"), added)
   103  	}
   104  	if len(removed) != 0 {
   105  		// TRANSLATORS: this is used to introduce a list of aliases that were removed
   106  		printChangedAliases(w, i18n.G("Removed"), removed)
   107  	}
   108  	w.Flush()
   109  	return nil
   110  }
   111  
   112  func printChangedAliases(w io.Writer, label string, changed []*changedAlias) {
   113  	fmt.Fprintf(w, "%s:\n", label)
   114  	for _, a := range changed {
   115  		// TRANSLATORS: the first %s is a snap command (e.g. "hello-world.echo"), the second is the alias
   116  		fmt.Fprintf(w, i18n.G("\t- %s as %s\n"), snap.JoinSnapApp(a.Snap, a.App), a.Alias)
   117  	}
   118  }